A Sister's Love
by Ezio 'The Doctor' Ichigo95
Summary: When Susan Test makes a new formula that makes whoever you want fall in love with you but Johnny is no longer around who will she test it on and what will happen between that person and her? Warning twencest don't like don't read.
1. Chapter 1

_This is just something I wanted to try please know this is a love story even though there is sex near the beginning it's not all about sex it's about Susan and Mary's relationship and every thing they have to face and deal with being twin lesbians in love with each other._

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This is the story of how me and Mary fell in love with each other, our adventures with each other and all the issues we faced. We hadn't been able to test on Johnny for almost 5 months now. It was hard not being able to test experiments on him. We had made so many breakthroughs but Johnny had been shipped away to military school because of _our _tests!

I recently created a new serum that would cause whoever you desired to fall deeply in love with you. But as I said no one to test it on. Except my sister Mary but I knew I'd have to trick her into drinking it and I had the perfect plan for it too. She would come home soon thirsty from her daily run and I would have some lemonade ready for us to drink.

She came home just as I finished preparing her glass. "Hey Susan." she greeted me walking into the lab drenched in sweat. "Hey," I replied back, "Made us some lemonade." I handed her the glass I prepared for her and hopped that she wouldn't notice that there was something different.

She took a sip and looked like she tasted something different uh ho. "Do I taste strawberry?" Mary asked "Y-Yes." I replied.

She quickly downed the rest of it I couldn't believe she drank it and didn't question it at all. "Time to change." she said as she started to take her sweat drenched jacket off. Wait why was she doing it in here in front of me, was the serum working and a side effect that she didn't care? Next she let down her long beautiful hair and it seemed like time had slowed down as I watched my beautiful sister undress. Wait what was going on I was infatuated with my sister this shouldn't be happening, I admit a couple times I had fantasized about my sister but this I couldn't rip my eyes away from her and she didn't seem to mind that I was just staring. Next she pealed of her shirt that had formed to her body and slowly reviled her covered breasts, her nice b cup perfectly rounded breasts, oh my god what was going on with me.

"M-Mary what are you doing?" I stammered as she went to take off her bra.

"What does it look like I'm changing clothes." She replied with no shame as her bra dropped to the floor showing hard erect nipples.

I couldn't believe what happened next, I stood up walked over to her and kissed her on the lips. What was the real surprise was that she kissed me back a deep passionate kiss. I gave into my desires I loved my sister and I always had I was just afraid to admit it because it was wrong for two sisters to love each other that way.

She then pushed me away but it wasn't because she was mad. She then slowly slipped her pants off to reveal that she had no panties on. I couldn't help but stair at her cleanly shaved tight wet pussy. She then smiled at me and kissed me again and as she did she slipped her hand down my pants. I grabbed her hand before she could touch my sopping wet pussy.

"N-No I'm not ready. Let's wait for tonight when we go to bed." I told her my heart pounding.

She nodded and pulled her hand out and went and got dressed. I could barely think all day and I could tell that Mary couldn't either I wanted her and she wanted me and that's all that mattered.


	2. Chapter 2

The rest of the day was a blur to me I remember some stuff but not much. I remember me and Marry kissing a lot in the lab. There was this one amazing time we where working on researching something for homework and then we started staring into each other's eyes I leaned over to kiss her and as we did she slipped her hand behind my head and the kiss became deeper. I let instinct take over and I softly bit her lip which made her moan and kiss me harder. My arms wrapped around her waist and pulled her close to me as I did her tongue licked across mi lips between my bites. I moaned and allowed her to slowly slip her tongue into my mouth. We slowly started making out as her hands dropped down and grabbed my hips and mine rubbed her back. Things would have gone longer and farther if dad hadn't called us down for a meatloaf surprise.

We went down for dinner and ate dad's meatloaf then had some family time watching TV. After that mom and mom and dad went up to bed and we acted like we where too. We figured that we had an hour before they actually went to sleep. During that time we talked about school and experiments we where coming up with in the lab. After an hour passed we decided before we try anything we should go check to see if they where asleep or not.

"I'll go" I volunteered and snuck to their room to find them fast asleep. I rushed back to our room my nipples getting hard. I entered the room to an already naked Marry, "Well," she asked "are they asleep?" All I could do was nod. She smiled and walked towards me and when she reached me she kissed me deep and grabbed my ass. I moaned and rubbed her back as we kissed. Then suddenly when I was least expecting it she pulled away.

Marry grinned "Now off with your clothes." She said in a very seductive voice. I slowly let my lab coat fall off and went to take my shirt off when she came over and stopped me, "Now now don't you want your sister to do that for you?" She asked. "Y-Yes please." I replied. She then came over and kissed me before grabbing the base of my shirt and slowly pulling up I lifted my arms up and let my shirt slip over my head and off my body. Marry was surprised that I didn't have a bra on but had a C cup already. She kissed right between my breasts and rubbed my stomach down to my pants. She unbuttoned my pants unzipped them then let them fall. I started to feel self continuous being this exposed to someone else.

"M-Marry?"

She looked and me worried "Yes, is something wrong?" She asked.

"Promise you won't tell anyone about this?" She nodded and kissed me which made me feel alright with her. She then pushed me to her bed and then laid me down. She then laid soft kisses down my body, leaving me moaning, down to my panties, which were soaked at the crotch. She then stopped and started rubbing my inner legs making me wetter and my nipples hard. Then when I wanted it the most but expected it the least she pulled my panties off to reveal my wet, tight, harry pussy. I gasped as the cold air hit my hot wet pussy I tried to close my legs but Marry wouldn't let me. She then got up and kissed up my body again this time it was amazing she started right above my pussy straight up landed one right on my belly button which sent me into a moaning frenzy. When she got to my breasts she did something different she started sucking on my right breast flicking her tongue over my hard nipple. I was so glad that we had a sound proof room so that mom and dad wouldn't hear me almost screaming already. Then suddenly she pulled off my nipple.

"Susan?" Marry asked.

I looked at her wanting her so bad "Y-yes Marry?"

"Have you ever been touched by another person down there?"

"I-I haven't even touched myself been to scared to." She nodded when I gave her that answer then softly kissed me.

"Then this might hurt and is going to feel a little strange." She told me and I just nodded.

Next she kissed me and then started rubbing my pussy lightly with a finger. After a couple minuets she started to tease me, I wanted her finger inside of me now! I moaned into her mouth as we kissed and next thing I knew her finger was slipping into my pussy. It felt so weird so foreign but soooo good I gasped as she did. She pulled away from the kiss with protest from me but she kept going slowly deeper into my pussy with her finger until it was all the way in. She then pulled her finger almost all the way out then slowly slipped it back in. Next she started to rub my clit with her other hand and that sent me over the top I grabbed the sheets and was all but screaming. She fingered me slow at first but slowly started to get faster making me moan louder. I was in excistacy, I was aware of nothing but me and Marry's finger in my pussy. Next thing I knew my pussy was clamping on Marry's fingers as I shook and something shot out of my pussy.

"Wow that was fast for your first orgasm." Marry sounded surprised.

I couldn't believe it I'd had my first orgasm, and I wanted another! Marry came up and whispered in my ear, "My turn." and nibbled on my ear.

She laid down next to me her smooth pussy glistening wet. I wanted to taste it! I started to kiss her and rub her breasts her moans quiet and muffled by me kissing her. I started to get curious and one hand started to wander down her body and soon got to her pussy. I started to rub it trying to rub it light like hers. It felt a little loose like there had been played with some.

"Marry have you ever orgasmed?"

"Of course sis how do you think I knew how to make you orgasm."

I then went down and kissed her shoulder and was rubbing her pussy a little faster. When she moaned from the kiss I let instinct take over and I opened my mouth and put it on her shoulder and stared to suck as I rubbed her pussy and I pushed down a little harder on it. I was a little surprised because I wasn't expecting that when I pushed down harder on her pussy I would actually enter it and Marry moaned louder as I kept sucking on her shoulder leaving her with a hickey. I started to finger her as she had me for a bit. I had totally lost track of time. After a bit Marry pushed me up.

"S-Susan I want you to taste me." She said pushing my body down.

I willingly went down kissing her as I did then when I got to her pussy I gave it one lick, oh how good it tasted. Her pussy had a bitter taste to it but it was oh so good. I then started licking it fast and Marry's moans started filling the room. After a while instinct took over again and I spread her pussy lips with two fingers and with the other hand started rubbing just above her clit. My tongue went between her pussy lips and I could taste her juices even more now and my tongue flicked over her clit and in that moment she screamed my name loud. "SUSAN YOUR TONGUE FEELS SO GOOD!" That sent me into a frenzy and I started licking even faster and started blowing into her opening. When I blew into her pussy it clamped a bit but for some reason I could tell she was far from orgasm. I rubbed fast above her clit and flicked my tongue over her clit causing her to grab the sheets and scream my name. After a while and I could tell she was close to an orgasm I went down and stuck my tongue inside of her entrance. I assume that sent her over the edge because just then her pussy clamped down on my tongue and then released it. It did that in a rhythmic pattern and as her pussy clamped on my tongue juices squirted out over my tongue and face. I lapped up all that I could then got up out of breath. Marry then grabbed me pulled me on top of her and kissed me. Then she did something that really surprised me, she whispered something in my ear. "I love you Susan Test."

I smiled and whispered back, "I love you too Marry Test." I then kissed her back and rolled off of her. She Turned over onto her side and started to cuddle, I could tell she was tired I smiled pushed her hair out of her face then cuddled back and that's where we fell asleep the night we admitted our love.


End file.
